Hi. I have worked as both a direct employee and as an outsourced resource. Typically, as a consultant you are engaged to work on a specific project often for a determined amount of time. Your goal is to complete said project and then you move on to the next clients project. As a direct employee, you are employed (hopefully) for awhile. You work with you manager on your career development, you set annual goals.
As a contract consultant, I have oftentimes felt like an outsider. On some of my longer engagements (3+years long), I have felt more like an employee and have been treated as one in many cases. Both have been rewarding, consulting and direct employee. I have found that as a consultant (which I did after 5 years as an employee), I gained a ton of insight consulting to many large organizations. Got to see how they work, what their cultures were like. I felt like it was necessary for me to progress. I learned a ton as a consultant. Hope this helps!